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A fiber integrated modulator is proposed based on a new kind of optical fiber with a fiber core on the inner wall.This optical fiber has a pore structure and its core is suspended on the inner wall of the pore.The magnetic fluid containing super paramagnetic Fe3O4 nanoparticles is synthesized,then it is encapsulated in the hollow optical fiber through molten connecting with a multimode optical fiber and used as the cladding of the fiber core.By an evanescent field,the magnetic fluid generates absorption effect on the light and its intensity is controlled by an external magnetic field,so that the light modulation is implemented.Moreover,the light at a wavelength of 632.8 nm is coupled in and out of the modulating element by tapering the coupling point.The experimental results show that only 2.0 × 10-2 μL of the magnetic fluid in the system can significantly impact the optical attenuation under different magnetic field strengths.When the magnetic field strength is 38 914 A/m,the saturation modulation depth is 43 %,and the system response time is below 120 ms.The system can also be used in light switches,optical fiber filters and magnetic sensors.

A new non-linear white balance method is proposed.Taking XYZ stimulus and RGB values of each color block in Munsell color chart illuminated by D65 light source as training samples.A BP neural network mapping relation is built between digit-image RGB values of standard Munsell color chart and XYZ stimulus.Then Estevens matrix is introduced,which is used in translating XYZ stimulus to cone stimulus.After non-linear calculation,the results are translated back into digit-image RGB,values and an image after white balance is produced.It is indicated that this method gives a correct result much closer to image of objects illuminated by standard light sources.In the case of high purity light sources,a large volatility exists in adjusting channel-gains,while a stable result using the proposed method.Especially when the purity of the light source is too high to make values of some color channel approach 0,the channels gain method is out of action,while a good correct result still can be achieved.Meanwhile,the mapping relation between RGB values of digit-image and XYZ stimulus is built,which is a still character for different lighting condition.

A method of electrospinning was established to fabricate organic silicon gel submicrometer optical fibers.First,Tetraethyl orthosiliate(TEOS) and n-Octyltriethoxysilane(Octyl-triEOS) were hydrolyzed and polymerized under an acidity condition.Simultaneously,the fluorescence indicator of tris(4,7-diphenyl-1,10-phenanthroline) ruthenium(II) chloride [Ru(dpp)3Cl2] was added into the solution to form a viscous sol solution.Then,the electrospun fiber with a diameter of 900 nm was obtained by electrospinning the sol solution under a high voltage of 10 kV in the electrostatic field.A tapered multimode optical fiber was coupled with the electrospun optical waveguide fiber through an evanescent field and the sensing characteristic of the electrospun fiber was tested at the same time.Experimental results indicate that the electrospun(4,7-diphenyl-1,10-phenanthroline) ruthenium(II) chloride doped silicon gel fiber has a smooth surface and a uniform diameter.The light can be highly coupled into the electrospun fiber through the evanescent field and can excite the indicator molecules in the fiber to emit a 595 nm fluorescence.This fiber is sensitive to the oxygen gas in the range of 0~100 %(volume ratio),and the quenching degree of I0/I is linear to the concentration of oxygen in the range.The response time is below 100 ms.